maintain an action against his or her master for ill usage, together with an application for habeas corpus if detained. However, such comments were not necessary for the decision in the case, and in law were only obiter dictum and not binding on subsequent courts. R v Stapylton One of the few non-commercial disputes relating to slavery arose in R v Stapylton (1771, unreported) in which Lord Mansfield sat. Stapylton was charged after attempting to forcibly deport his purported slave, Thomas Lewis. Stapylton's defence rested on the basis that as Lewis was his slave, his actions were lawful. Lord Mansfield had the opportunity to use a legal procedure at the time in criminal cases referred to as the Twelve Judges to determine points of law (which were not for the jury) in criminal matters. However, he shied away from doing so, and sought (unsuccessfully) to dissuade the parties from using the legality of slavery as the basis of the defence. In the end Mansfield directed the jury that they should presume Lewis was a free man, unless Stapylton was able to prove otherwise. He further directed the jury that unless they found that Stapylton was the legal owner of Lewis "you will find the Defendant guilty". Lewis was permitted to testify. The jury convicted. However, in the course of his summing up, Lord Mansfield was careful to say "whether they [slave owners] have this kind of property or not in England has never been solemnly determined." James Somersett's case The question of a slave's rights as against his putative master (as opposed to merchants' rights as against each other) eventually came before Lord Mansfield and the King's Bench in 1771. A writ of habeas corpus had been issued to secure the release of James Somersett, a black man confined in irons on board a ship arrived in the Thames from Virginia, bound for Jamaica, and the return stated that he was a slave under the law of Virginia. Lord Mansfield was anxious to avoid the issue principle, and pressed the parties to settle; but the case was taken up by the West India merchants, who wanted to know whether slaves were a safe investment, and by abolitionists such as Granville Sharp, so that it became a cause célèbre. Delivering his judgement, Lord Mansfield stated that slavery was so 'odious' that it could only be introduced by positive (i.e. statute) law,